I'm at a loss on this one.  I tried a few different methods of wrapping the tests in load_tests(), I tried doing support.threading_setup() in setUpModule and support.threading_cleanup() in tearDownModule, tried the same in each test class (following the example of test_asynchat.TestAsynchat).  Every way I've tried, I still get the warning that threading._dangling was modified when running the test as part of regrtest, even though it appears that everything is getting called at the right time with the right arguments.

I did just stumble onto something interesting: if you simply remove the decorator and finally clause from test_main and run it (with the initial discovery patch applied), there is no warning at the end.  Remove test_main and there's the warning.  Add a load_tests that builds a suite in what appears to be the same order as what support.run_unittest does, and the warning is still there.  I can't find what makes the difference.

The attached diff is the best I've come up with that seems to do the right things with the reap functions, but still causes the warning on my machine.

Am I missing something obvious here or what?